All vehicles pass through a fluid environment as they move. For example, cars and airplanes move through air, boats move through air and water, and submarines move through water. As these vehicles move through their fluid environment, the fluid (e.g., air or water) is slowed down by the frictional resistance of the surface area of the body of the vehicle. This creates a layer of turbulent fluid flow that circulates along the vehicle slower than the fluid flow that is not in contact with the surface area of the vehicle. The varying speeds of fluid layers meet behind the vehicle, or any protuberances thereon, such as mirrors, wheel wells, rudders or propellers, as the vehicle moves through the fluid at differential rates so as to form a low pressure area, or vacuum immediately behind the vehicle, or its protuberances. The turbulent layer and vortices create a drag force, which opposes the motion of the vehicle through the fluid environment. In this way, the front, sides, top, bottom, and even rear of a vehicle can contribute to the drag that vehicle suffers while in transit through the fluid environment.
One aspect of the drag force caused by fluid resistance is that caused by trailing vortices that result from the vehicle moving through the fluid, the so-called turbulent flow. Depending upon the shape and form of the vehicle, a variety of vortices can be formed along all surfaces of the vehicle. These vortices in the fluid hold the vehicle back, increasing the energy needed to move the vehicle forward. Another aspect of the drag force caused by fluid resistance involves the frictional resistance of the fluid as it passes over the various surfaces of the vehicle.
As a result of this, the speed and efficiency of a vehicle moving through the fluid environment is limited not only by the drag forces created by turbulent flow, but also by drag forces caused by frictional fluid resistance to the surface of the vehicle, which depends on the amount of fluid traveling along and past the vehicle.
Furthermore, the amount of drag caused by these sources is directly related to the amount of fuel needed to move the vehicle. As a result, much effort is made to design aerodynamic or hydrodynamic vehicles that minimize the amount of drag on the vehicle.
Unfortunately, compromises must be made in vehicle design to accommodate other parameters than just fluid resistance. Engine design, passenger comfort, safety requirements, cargo space, and even aesthetics can mean that a vehicle's design creates many undesirable vortices as it passes through its fluid environment.
It would therefore be desirable to provide a device to control the flow of a fluid as it flows past the surface of a vehicle to retard the creation of vortices that create drag against the vehicle. It would be further desirable to make this device easily attachable or detachable so that it could be more effectively added to existing vehicles or added after market.